CHICAGO (AP) - Antawn Jamison's ailing shoulder will keep him off the court well into the regular season.

The Washington Wizards announced an estimated recovery time for Jamison's injury Friday, saying he's likely to miss the first eight to 13 games.

"The most important thing is it's a long season," he said. "We've got some guys who we added to the team and can help us out. I've just got to do what I've got to do as far as rehab and get ready as quickly as possible."

The two-time All-Star forward partially dislocated his shoulder trying to block a shot in an exhibition game against Cleveland on Oct. 14. The Wizards originally ruled him out for the rest of the preseason until the injury could be reevaluated this week.

"We can hold down the fort until he comes back, and we're going to have to," forward Caron Butler said before Friday's game at Chicago.

Team president Ernie Grunfeld said doctors have had a chance to look at the shoulder again, and that Jamison is expected to be out three to five weeks. Jamison said he feels "great" and that he's able to lift weights and dribble the ball. He can't shoot, and he can't afford to aggravate the injury.

"The biggest thing for me is to, even though I feel great, still continue to work, still stick with somewhat of a timetable," he said. "I feel good. I've been lifting, dribbling the ball. They won't let me shoot yet, but I'm doing whatever the doctors tell me to do. But I feel pretty good."

Losing Jamison is another blow for a franchise that has had three straight seasons marred by injuries to marquee players.

"You always want to be at full strength when you can," coach Flip Saunders said. "It's a good challenge for the rest of the guys on the team. We're trying to be conservative with it. It's not a situation where we think he's going to miss extended time. Because of that, it'll give other guys a good opportunity."

Gilbert Arenas and Brendan Haywood barely played last season, and DeShawn Stevenson missed more than half of the games as the team finished 19-63, one of the worst marks in franchise history. Jamison had a healthy year, missing only one game and leading the team in scoring at 22.2 points per game. He also averaged 8.9 rebounds.

"It continues to happen," said Butler, who has missed 58 games over the past three years with various injuries. "We're going to remain optimistic and remain positive and see what happens."

Andray Blatche and offseason acquisitions Fabricio Oberto and Mike Miller will vie for more playing time during Jamison's absence.

The Wizards open the season in Dallas on Tuesday.

"Everyone goes through sequences where they lose some players," Saunders said. "You don't want to have extended time. You'd better lose somebody early rather than lose them late."